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Re: Foursevens Quark Tactical QT2L-X Burst Mode review

Originally Posted by ti-force

Thank you very much for the kind words. It's greatly appreciated. To answer your question, yes, the model I reviewed is pulse width modulated.

Curious what modes you found PWM on. AFAIK, all Quarks are current regulated for all their constant on modes (don't know about the disco modes though). I have the 2L burst mode head and just did time exposure sweeps across a camera for all the loose bezel modes and L, M and H all look completely smooth like the center beam here (L2R @ ~3 lms - MDC AA, QPA-X, Mini MA):

However, on moonlight, there is some "warble" (as discussed in the PWM sticky) on my sample. Somewhat rare among my Quarks, but most are low voltage XML heads.

Re: Foursevens Quark Tactical QT2L-X Burst Mode review

I thought I tested the aa version of this light with a 14500, but if I did I can't find my notes on it. I'm pretty sure I tested it, but I'm thinking the output was basically the same as 2xaa batteries so I ended the test. I did test the burst mode light with an AW IMR 14500. The results are in post # 13 of this thread -

Re: Foursevens Quark Tactical QT2L-X Burst Mode review

Originally Posted by ti-force

I thought I tested the aa version of this light with a 14500, but if I did I can't find my notes on it. I'm pretty sure I tested it, but I'm thinking the output was basically the same as 2xaa batteries so I ended the test. I did test the burst mode light with an AW IMR 14500. The results are in post # 13 of this thread -

Forgive my knuckleheadedness, but you got a 2X123 light to work with 1X14500?

I understood the graph, and thank you for that, but I admit to being unclear about using the 14500 in a 123 light. Or was this some kind of Lego thing? I guess it`s one more thing you hardcore flasha-battery-aholics can pull off.

Re: Foursevens Quark Tactical QT2L-X Burst Mode review

Originally Posted by Treeguy

Forgive my knuckleheadedness, but you got a 2X123 light to work with 1X14500?

I understood the graph, and thank you for that, but I admit to being unclear about using the 14500 in a 123 light. Or was this some kind of Lego thing? I guess it`s one more thing you hardcore flasha-battery-aholics can pull off.

Yes that's it exactly. All you need is an aa body. All of the variants use the same parts. Threads are the same, all tailcaps are the same, all heads are the same, just electronics inside the head and reflectors are different to correspond with different led's. The only thing you need to be aware of is the fact that it is possible to put an aa/2xaa/1xcr123, i.e., low voltage head on a 2xcr123 body/battery tube and cause permanent damage to the electronics in the head due to overvoltage.

Re: Foursevens Quark Tactical QT2L-X Burst Mode review

Originally Posted by reppans

Curious what modes you found PWM on. AFAIK, all Quarks are current regulated for all their constant on modes (don't know about the disco modes though). I have the 2L burst mode head and just did time exposure sweeps across a camera for all the loose bezel modes and L, M and H all look completely smooth like the center beam here (L2R @ ~3 lms - MDC AA, QPA-X, Mini MA):

However, on moonlight, there is some "warble" (as discussed in the PWM sticky) on my sample. Somewhat rare among my Quarks, but most are low voltage XML heads.

My mistake, I accidently picked up an older version 1 Quark x without burst mode. I've been away for a while. I'm a little rusty. Anyhow, the burst mode light doesn't use pwm as I just checked it, but the older Quark x I have does use pwm. Maybe it's a prototype? When I was still doing reviews, Foursevens would sometimes send me prototypes to test.

Re: Foursevens Quark Tactical QT2L-X Burst Mode review

Re: Foursevens Quark Tactical QT2L-X Burst Mode review

Originally Posted by ti-force

My mistake, I accidently picked up an older version 1 Quark x without burst mode. I've been away for a while. I'm a little rusty. Anyhow, the burst mode light doesn't use pwm as I just checked it, but the older Quark x I have does use pwm. Maybe it's a prototype? When I was still doing reviews, Foursevens would sometimes send me prototypes to test.

Yeah, your photo looks like it could be an extreme case of that "warble" issue. Did you notice this behavior on all lower modes of your sample/prototype, as is usually the case for a true PWM light?

Anyways, here's a sample of my Quark Xs on moonlight. L to R, QP2L-X BM, QB2L-X (not BM), and QP2A-X, with a Mini MA for PWM reference. The QP2L-X BM has some of that warble thing going (as I mentioned above), but it's not true PWM. All three Xs look well current regulated on L,M and H, just like the bottom picture/horizontal lines.

BTW, I want to thank you for your reviews and resolving what are true ANSI lumens here on CPF.... your lumen scale seems ~25% different (which is huge in my mind) than another CPF reviewer for the same light (QP2A-X). I know the potential for sample variation, but I also run a lightbox, calibrate using various QP2A-Xs, peg the stepdown (which should be more consistent than max) at what you do, and can match most or all of the modes on the light. This scale (your scale) also matches most of my light collection, so I have the most faith in your output numbers.

Re: Foursevens Quark Tactical QT2L-X Burst Mode review

Yeah, your photo looks like it could be an extreme case of that "warble" issue. Did you notice this behavior on all lower modes of your sample/prototype, as is usually the case for a true PWM light?

Anyways, here's a sample of my Quark Xs on moonlight. L to R, QP2L-X BM, QB2L-X (not BM), and QP2A-X, with a Mini MA for PWM reference. The QP2L-X BM has some of that warble thing going (as I mentioned above), but it's not true PWM. All three Xs look well current regulated on L,M and H, just like the bottom picture/horizontal lines.

BTW, I want to thank you for your reviews and resolving what are true ANSI lumens here on CPF.... your lumen scale seems ~25% different (which is huge in my mind) than another CPF reviewer for the same light (QP2A-X). I know the potential for sample variation, but I also run a lightbox, calibrate using various QP2A-Xs, peg the stepdown (which should be more consistent than max) at what you do, and can match most or all of the modes on the light. This scale (your scale) also matches most of my light collection, so I have the most faith in your output numbers.

Great job ti-force.... review more lights please .

Thanks for the kind words. When I checked my sample it appeared as if it was pwm in every mode except max mode. I'll check again

Re: Foursevens Quark Tactical QT2L-X Burst Mode review

Just checked the original Quark X again and all the lower modes are pwm on my sample. The higher the brightness the faster it's pulsed, but I see it with my eye when I wave it in front of my face. Could be they used a slightly different circuit on my sample. Usually if I was sent a prototype it was a final iteration, but maybe that wasn't the case with this one. Strange.

Re: Foursevens Quark Tactical QT2L-X Burst Mode review

I just got a set of Keeppower 16650 2500mAh li-ions for this light from Illumination Supply, and WOW. They fit like they're made for the light, and I'm getting just over 100 minutes of runtime at the highest setting before any dimming, which exceeds the OPs runtime test with PRIMARY cells! And this is before doing any break-in of the new cells. After 105 minutes or so, it begins to fade slowly with these batteries, letting you know it's time to swap batteries, rather than leaving you suddenly in the dark like protected RCR123a does in this light.

Re: Foursevens Quark Tactical QT2L-X Burst Mode review

Originally Posted by Raphion

I just got a set of Keeppower 16650 2500mAh li-ions for this light from Illumination Supply, and WOW. They fit like they're made for the light, and I'm getting just over 100 minutes of runtime at the highest setting before any dimming, which exceeds the OPs runtime test with PRIMARY cells! And this is before doing any break-in of the new cells. After 105 minutes or so, it begins to fade slowly with these batteries, letting you know it's time to swap batteries, rather than leaving you suddenly in the dark like protected RCR123a does in this light.

I am pleased with the same set up, though my favorite remains using a single AA tube with an AW IMR 14500 cell.